Theoretically Possible
by Rachel500
Summary: He was looking forward to spending Thanksgiving with Carter so obviously Jack wakes to find himself in another universe, which seems all too familiar...


Stargate SG1 is somebody else's, probably MGM/Gekko Corp/Sci-Fi, and I freely admit that whoever's it is, I'm borrowing their show and they retain all rights, etc.

**Author's Notes: **Sam/Jack. Written for the GW Shipsgiving 2012. Spoilers for SG1. Set post show. This is a Stargate/Star Trek fusion but only in the loosest sense so I'm not labelling it as a crossover. While I haven't read anything similar to this, I'm pretty sure the concept has been done before in fandom somewhere, possibly because it seems such an obvious concept to do that I can't believe I'd be the first to pick up the bouncy plot bunny. Anyway, this is my take on the idea. Happy Belated Thanksgiving to those across the pond!

**Theoretically Possible**

Jack wakes up and groans out loud at the bright shining light that's directed at his eyes. He bats it away, annoyed.

"Captain, glad to see you're back with us."

And Jack freezes at that because, firstly, he hasn't been a Captain for more years than he likes to think about and secondly, he hasn't heard _that_ voice since Janet Fraiser died. He squints at the fuzzy form shaping up as the light disappears and his eyes adjust.

"Doc." He says carefully.

Janet's warm brown eyes twinkle at him but the line of her mouth is stern. "Do you remember what happened, Captain?"

Jack goes to shake his head and stops because the pain is somewhere between the headache he'd had when he'd had skull fractures and the hangover from hell that he'd been given on the planet with the very nice fruity cocktails.

"No?" He says instead. Because the last thing he remembers is getting in bed with his wife in anticipation of actually spending Thanksgiving together since Sam's ship was in orbit for once and not running around saving the universe from imploding or exploding or something.

"You collapsed." Janet says succinctly.

OK. So this Captain guy collapsed and now he – General Jack O'Neill – has ended up in an alternate universe where Janet is still alive.

He needs more data. He shifts carefully into a sitting position and frowns heavily at the surrounding bland room.

He's in some kind of infirmary which isn't a surprise; medical beds line the wall equipped with advanced technology that rings a bell but which he can't quite put his finger on. Then he gets a load of Janet's uniform and his eyebrows shoot up fast enough that he thinks they're going to sprain themselves. Her uniform – if it can be called a uniform – consists of a form fitting dress in blue and black which has an insanely short skirt and knee-high brown leather boots. It looks familiar. Was she on her way to a Star Trek convention? Halloween party? Only the ever-present medical coat says that she's on duty.

"There's no medical reason for your collapse according to my tricorder so I'm going to go with alien influence." Janet continues. "Commander Carter and Doctor Jackson are reviewing the datalogs from your last mission to see what you touched."

Jack nods carefully. Right. So, aliens are usual, normal, de rigour. That's good. The terminology though belongs to fiction. Unless this universe decided to model their Stargate programme after the very popular TV show. It was possible, wasn't it? He stared again at Janet's uniform. He just couldn't see the women in the Air Force ever consenting to wear something like that seriously without a whole load of men getting punched.

His eyes catch on his hands curled around the edge of the bed and he frowns. They look younger; young. He pats himself down absently and realises he's in a uniform; gold tunic top, black pant, black boots. He feels slimmer; fitter. The desk job has been hell on his figure.

The doors of the infirmary slide open and he brightens at the three familiar faces walking towards him.

Daniel looks bizarre in the red tunic and black pants combo but not as bizarre as Teal'c who is wearing the same. Sam has a blue science dress that matches Janet's except her boots are black rather than brown and she's without a medical overcoat which means Jack gets the full benefit of just how form fitting the dress is.

Maybe, Jack considers, this is a dream. Who knew he had a Star Trek kink?

Sam's elfin cut reminds Jack of former years. Her face – so young and open in a way that his Sam hasn't looked since…since forever which makes Jack's heart hurt a little – brightens at the sight of him. "Good to see you're awake, sir."

"Indeed." Teal'c says, as they form up in front of him. Teal'c stands in a familiar fashion; hands clasped behind his back, face impassive.

Jack nods at him.

"Well," Daniel shoves his glasses up his nose and Jack marvels at the floppy hair because his Daniel's hasn't been floppy in a long while, "we've isolated what you touched on the planet and I've conferred with Nyota about the inscription and…well, it's fascinating really and I can't really make much of it other than something to do with different paths and roads and…"

"So…" Jack interrupts before Daniel gets carried away, "here's the thing; either I'm having a very, _very_ odd dream because I ate too much cheese last night which is a possibility, or I'm not your Jack O'Neill."

Sam's eyes widen as Teal'c reaches for the stun gun in its holster and Jack hurriedly holds up both his hands.

"Alternate universe." Jack says quickly. "Not the evil mirror one because you know that would be cliché and you know how I feel about clichés." He pauses. "Well, my Sam, Daniel and Teal'c know how I feel about clichés."

"Oh boy." Sam says.

Teal'c stuns him anyway.

o-O-o

"So I take it this isn't the Enterprise?" asks Jack fiddling with the tiny (tiny!) fork and the tray of what appears to be regurgitated mush from the replicator.

He'd woken up for the second time in the infirmary with an unapologetic Teal'c glowering at him although his expression had turned mildly approving when Jack had praised him for shooting him despite Janet's remonstrations about discharging weapons in her infirmary. Daniel got excited and went off somewhere chasing down additional facts and Sam had sweet talked the Doc and Teal'c (who turns out to be the Chief of Security – no surprise there) into letting her take Jack for some food. He knows her whole ploy is to get him to talk to her and give up intelligence because he knows her counterpart too well to be fooled but he'll play along.

Sam grins at him across the table in the mess and shakes her head, blonde hair catching the lights. "I think Captain Kirk might have issues with that."

There's actually an Enterprise and a Kirk? Jack blinks at her.

"This is the U.S.S Cheyenne; we're the best in the fleet." She beams proudly at him.

"I think Kirk would have issues with you claiming to be the best in the fleet." Jack retorts.

She laughs. "I take it you have a Jim Kirk in your universe then?" Her curiosity is written all over her face.

"Kinda," Jack evades, "so you and the rest of this merry Cheyenne crew; you're what? Two years together as a team?"

"About that. This is our third year together." Sam agrees. "After the Enterprise returned from its first five year mission, Commander Spock and Captain Kirk made a case that there was a need for first contact specialists and the Cheyenne was ready so…Admiral Hammond put us together." Her blue eyes take on a familiar perceptive gaze. "You've been together as a team for longer?"

"My team was called SG1," Jack replies, scooping up some of the mush, "we were together for seven years, served together in the same command for another year, and we're still all part of the same programme what, five years later?"

"But it's not Starfleet." Sam states with a careful deduction.

"No, not Starfleet." Jack confirms. "We discovered a device in Egypt that allows travel to other planets through a wormhole. We have spaceships now but we didn't when we started."

"A device that creates a wormhole?" Her whole face lights up.

"Don't look at me like that," Jack jokes, "my Sam's the one to explain how it works; I just travel through the damn thing."

"She's your science officer?" asks Sam unable to resist the lure of checking out her counterpart.

"She was," Jack explains, "and my second-in-command. She has command of the General Hammond now – one of our best spaceships. She helped design it."

"General Hammond as in George Hammond?" Sam checks.

Jack nods. "I assume he's the Admiral you mentioned, right?"

"OK, so wow." Sam shakes her head. "Having my own command seems so far away."

Jack shrugs and points his fork at her. "You'll get there. I never thought I'd make General either but…" he makes an exaggerated grimace and Sam laughs and ducks her head. He wonders if her Jack O'Neill loves her; if she loves him. He crams more mush inside his mouth to prevent himself asking the question.

"You seem OK with the alternate reality thing." Sam comments.

Jack swallows and nods. "We've run into a fair few. Actually, my first encounter with one was in our third year of the programme."

Sam smiles. "So the major events of our universes may differ in detail but not content?"

"Oh, no. There's a lot that's different here." Jack replies dryly. "The date for one."

"Your universe is situated in our future?" guesses Sam.

"Past." Jack corrects and scoops up more mush. It's not bad mush; tastes vaguely of the chicken stew it's pretending to be.

Sam can barely contain her interest. "Really?"

"Really." Jack confirms. "It's the year twenty-twelve where I'm from."

Sam stares at him.

"But I seem to recall you, or rather alternate you from the first alternate universe I encountered, said something about there being infinite possibilities and time may operate differently in each universe?" Jack shrugs again, faking indifference and ignorance. He finishes his mush while Sam's brain ticks away loudly.

"I have to admit I'd love to see your universe." Sam says wistfully. She bites her lip. "Are you certain it's not something you did that brought you here?"

"Nope." Jack says. "I think it's whatever your Jack touched when he shouldn't have been touching things on strange alien planets. I was in bed with my wife."

"Sara?" inquires Sam delicately.

"Not Sara." Jack replies. "We didn't make it after our son Charlie died. I take it…" There's a flicker of hope because this universe is so very different. Maybe Charlie is still alive…but no, Sam's face has taken on an all too familiar compassionate sympathy.

"Captain O'Neill is divorced. His son was killed in a phaser accident when Charlie was seven." Sam explains gently.

Jack nods jerkily. "Guess our universes aren't so different."

Sam turns her attention to the food and Jack suddenly wishes he was home already.

o-O-o

Daniel waves a hand at the monitor with all the wiggly lines displayed upon it as though it will explain why Jack has ended up in his own personal Star Trek universe.

"Words, Daniel." Jack prompts from his place in the team huddle around the computer station.

Daniel's annoyed look is consistent across universes. It's an important fact. One that Jack will relay to his Daniel in order to get the same annoyed look gazing back at him just to prove that they are indeed the same annoyed look.

"Our Jack O'Neill touched this altar on this planet," Daniel explains, and wow – the lecture tone is also very consistent across universes. "Alberra was visited by the Enterprise in their first year of exploration only the visit didn't go well…"

"A red shirt died?" Jack guesses as he rocks back on his heels and wishes they'd put pockets in the damn pants.

"No, well, not exactly." Daniel gestures with his hand again. "Ensign Gene Roddenberry touched the altar and disappeared about a day later."

"They thought he was dead, right?" Jack guesses.

Daniel shoots him a look.

Sam takes pity on Daniel. "We think he was transported to another universe."

Jack doesn't say he recognises the name, but it's easy enough to make the connection that perhaps someone made a TV show out of the universe they'd left behind and were unable to get back to when all the evidence is around him.

"Only it went differently for you and Jack. Obviously." Daniel says.

"Obviously." Jack repeats dryly.

"We think in the first instance, the ensign didn't have a counterpart in whatever universe he ended up in," Sam says enthusiastically, "so he disappeared rather than his spirit swapping bodies. Unfortunately in discussing the situation, the talks with the Alberrans went badly, and the Enterprise crew had to leave the planet in a hurry…"

"Kirk slept with someone didn't he?" Jack guesses again.

Daniel glares at him and Jack smirks. Ah, but he misses this. His own Daniel is far too immersed in his own projects to come and snark at him on a daily basis.

"It was the High Priestess." Teal'c confirms solemnly.

"And that is why you're my favourite, T." Jack pats his shoulder.

Teal'c raises the eyebrow but he's pleased; Jack can tell.

"Anyway, on _our_ visit, we managed to broker a good peace treaty with the Alberrans." Daniel continues a little huffily.

And Jack puffs up proudly. There's no doubt in his mind that this crew, this team, are the best regardless of the Enterprise.

"So we've altered course and should be there within a couple of hours at our maximum speed. Chief Engineer Siler is happy our warp engines can take it." Sam adds. "We're certain we'll be able to find a solution and have you back in your own universe soon."

"Excellent." Jack says sincerely, because it really is. "Hopefully I'll be in time for the turkey."

"Turkey?" Daniel asks inquisitively.

"Thanksgiving." Jack explains succinctly.

Sam frowns suddenly. "Sir, you said you were in bed with your wife when you were transported here?"

"At my cabin in Minnesota." Jack agrees brightly. "We both got vacation this year."

They all frown at him.

"What?" asks Jack impatiently.

"It's just…well," Daniel adjusts his glasses nervously, "you're not worried about our Captain O'Neill waking up in bed with your wife?"

Jack thinks about Sam's reaction when she realises the man in bed with her isn't _Jack_ and smirks. "Nope."

Sam looks worried. It's her 'I'm worried about Jack' look and it's disconcerting to know that it's for his counterpart not for him. "He won't be harmed though, right?"

He sighs as he takes in their combined concern. "He'll be ten years older, out of shape, and grumpy because Carter will have kicked his ass before he can get to touch something he shouldn't." He says bluntly. "He'll be fine."

"Carter as in…" Daniel points at Sam.

Jack nods.

Daniel looks at Sam wide-eyed. "You and _Jack_?"

Sam blushes bright red. "Infinite universes, Daniel. It is theoretically possible…"

"More than theoretically." Jack interrupts. "We've been married in pretty much every universe we've encountered except for when I've been dead, or you've been dead, or there was that one where I was a frozen popsicle and you married McKay."

"McKay?" Her voice is a mix of horror and fascination. "_Rodney_ McKay?"

"An unusual choice." Teal'c comments.

"I know. If it helps, Carter said that whole universe was screwed." Jack says helpfully.

o-O-o

The away team is small. Daniel is left to do his thing with the High Priestess who, pretty much like any High Priestess back in Jack's universe, seems to have a thing for Daniel who as usual is completely oblivious. He wonders if Daniel got accidentally married to someone in this universe.

Sam leans in closer to him. "I, um, wanted to ask…"

"We served together for eight years before we got our acts together." Jack informs her briskly. "Best decision I ever made was to be with her." He turns and smiles warmly at her. "You should tell him when he gets back."

"He…the Captain doesn't see me that way." Sam says quietly.

But she loves him. That's as plain as day. Jack wonders whether his Sam ever looked at him with that expression of wistful longing in their third year and whether he'd just been too blind to see it, drowning in his own want and need for her.

"He does." Jack corrects her.

But he remembers his universe; of hearing of the possibility of him and Jack from Daniel's trip to an alternate universe and dismissing it because he was so careful not to think of Sam that way (because he wanted her in truth); of meeting Sam's alternate and kissing her (and wanting it to be his Sam he was kissing); of knowing he loved his Sam, his Carter, long before he was ready to admit it (before blue force shields and za'tarc machines brought his feelings into the open).

So maybe the truth is that Captain Jack O'Neill isn't ready to admit he loves her and maybe Lieutenant Commander Samantha Carter isn't ready to admit she loves him either. Every universe runs on its own time.

"Uh, Jack?" Daniel ushers him forward.

Jack turns to Janet who insisted on coming along as the CMO. "It's been great to see you again, Doc."

Janet nods, a flicker of understanding that she hasn't survived in his universe crossing her face.

Teal'c gives him a bow of farewell as Jack and Sam walk up to the altar.

"Just push here." Daniel points at the altar and a small square with what looks like the Stargate symbol for Earth.

"Thanks, Daniel." Jack says sincerely. "I always knew you'd get me home."

Daniel smiles briefly at the praise and moves away to join Teal'c.

Sam puts on her brave face. "It's been a pleasure, sir."

Jack nods and hesitates as he reaches for the square. He moves to whisper something in her ear and she flushes as she listens but she does listen and when he steps back, her eyes are bright with abashed confusion and a cautious delight. He gives her a final wave, and taps the square.

o-O-o

Somehow, Jack isn't surprised when he jerks awake to find himself handcuffed to the iron wrought headboard that adorns the bed in the cabin. He's vaguely amused that the handcuffs are the pink fuzzy ones that Vala had given Sam the year before at Christmas.

"Jack?"

He immediately turns to the doorway and the sight of his Sam stood there with a hopeful expression. He soaks in the differences; the things that make her his Sam, his Carter; the lines that bracket her mouth, the experience shining from her eyes, the more rounded figure that's dressed conservatively in jeans and a bright blue sweater that brings out the blue in her eyes, the long hair that tumbles over her shoulders because she'd stopped pretending she preferred her hair short.

"Carter." Jack says cheerfully. "Did I miss the turkey?"

Her face lights up the room as she dives across the space between them to kiss him.

Jack is contemplating whether he should suggest they put the handcuffs to the use Vala intended when a shriek has them both jumping away from each other.

"My eyes!" Cassie complains. "Can't you guys get a room?"

"We have a room." Jack points out, ignoring his own embarrassment at being caught handcuffed to his bed and kissing his wife by the young woman who is effectively a surrogate daughter to every member of the initial SG1. "Not our fault you're in it." He frowns at her. "Why are you in it?"

Cassie rolls her eyes at him. "Teal'c says dinner is almost done and you should hurry up before Daniel eats all the pumpkin pie."

"Oh," Jack says hopefully, "pie."

"And turkey." Sam says fondly. "Come on. You can shower and get ready while I call off the SGC sending people to take you into custody."

"_We _could shower." Jack waggles his eyebrows at his wife.

"Jack!" Cassie shrieks and hurries away.

Jack sighs as Sam uncuffs him and rubs his wrists. "How long did it take you to notice it wasn't me?"

"As soon as he woke up. He stared at me like he'd never seen me naked." Sam states matter-of-factly. She brushes a kiss over his lips. "It sounded like a fascinating universe from what little he told me."

Jack figures that Captain O'Neill probably went with the name, rank and serial number for a while until Sam wore him down and he told her something. She never has to wear Jack down these days; he caves pathetically quickly. "You weren't married to McKay." He offers.

Sam laughs and the sound makes him happy.

It carries him through his shower, through the meal with Teal'c, Daniel and Cassie where they pass dishes around to each other and Jack tells them about his most recent alternate universe experience. Teal'c muses out loud whether there is a Star Wars universe and they debate the possibility through dessert. During coffee, Cameron Mitchell calls from Kansas where he and Vala are having Thanksgiving with Mitchell's folks and Jack sneaks out to the deck with a bottle of beer while the others catch up with the missing members of the rest of SG1.

He breathes in the crisp Minnesotan air and enjoys the starry sky.

Sam slides into place beside him; natural and easy and as though she was always meant to be there. He wraps an arm around her to bring her closer and she snuggles into his side.

"You OK?" Sam asks.

"Just…" Jack drops a kiss on the top of her head. "Glad I'm not, you know, stuck in another universe."

"You think they'll get together? That Sam and Jack?"

"It's theoretically possible." Jack jokes lightly.

She hides her grin and ducks her head. "No, seriously."

"Well, seriously," Jack teases and evades the poke in the ribs she aims at him before settling back beside her and tugging her closer still, "seriously," he says, "I told her when he asks her to go fishing, she should say yes."

Sam smiles at him. "And will she say yes?"

He holds her eyes. "Eventually."

"Hmmm," Sam says, "that's because she's smart." She rolls her eyes and gives a self-deprecating smile. "Eventually."

Jack kisses her.

And kisses her.

And thanks his universe that he and Sam worked out that they love each other and are together; will love each other forever if Jack has his way - after all, it's theoretically possible.

The End


End file.
